Peripheral arterial disease (PAD) is a debilitating condition affecting between 8 and 12 million people in the United States. Patients with PAD of the lower extremities are subject to periods of intermittent claudication pain. Gait changes such as reduced stride length, cadence and walking speed are reported in patients with PAD. Walking exercise has been prescribed as the primary mode of rehabilitative treatment in patients with PAD. An enhanced form of walking exercise, polestriding, has been found to improve rehabilitation outcomes for patients with PAD. Walking with poles also increases stride length, cadence and walking speed and decreases ground reaction forces on the joints. Changes in walking mechanics secondary to walking pole use may allow more time for perfusion of the leg muscles thus delaying the onset of and decreasing the severity of ischemic pain. Thus, we hypothesize that polestriding may be superior to walking exercise in the rehabilitation of persons with PAD. The two therapies however, have never been compared in a randomized trial in this population. Specific Aims: The primary specific aim is to compare the effects of a 24-week walking versus polestriding exercise in patients with PAD on exercise endurance, perceived physical function and walking abilities. The secondary aim is to explore biomechanical and physiologic mechanisms to explain the expected differences observed in the polestriding and walking groups. Mechanistic variables include perceived claudication pain, gait biomechanics, tissue oxygenation in the most severely affected leg and daily physical activity. Design: A randomized, controlled clinical trial will be used to compare the effects of polestriding and walking exercise. 180 patients will be enrolled in the study to randomize 126 (n=63 in each group). Baseline testing will consist of treadmill exercise, completion of functional assessment questionnaires, gait analysis, and physical activity measurement. Subjects will then be randomized to a 24-week walking or polestriding program. Subjects will exercise three times weekly for 30-60 minutes. Duration and intensity of exercise will be systematically increased. Subjects will be re-tested at 6, 12, and 24 weeks. A final testing battery will be completed at 32 weeks to assess how well subjects have maintained fitness gains. Analysis: Data will be analyzed using descriptive statistics, repeated measures ANOVA and linear regression analysis. Potential co-variates such as smoking and medication use will be monitored and analyzed.